1. Field of the Invention
The present invention relates generally to tissue treatment systems and in particular to methods and compositions for detecting infection in a wound.
2. Description of Related Art
Clinical studies and practice have shown that a system for providing a reduced pressure in proximity to a tissue site augments and accelerates the growth of new tissue at the tissue site. The applications of this phenomenon are numerous, but application of reduced pressure has been particularly successful in treating wounds. This treatment (frequently referred to in the medical community as “negative pressure wound therapy,” “reduced pressure therapy,” or “vacuum therapy”) provides a number of benefits, including faster healing and increased formulation of granulation tissue. Typically, reduced pressure is applied to tissue through a porous pad or other manifolding device. The porous pad contains cells or pores that are capable of distributing reduced pressure to the tissue and channeling fluids that are drawn from the tissue. The porous pad often is incorporated into a dressing having other components that facilitate treatment.
One difficulty associated with the use of such systems is detecting the presence or type of infection present in the wound without disturbing the airtight dressing covering the wound. Numerous methods have been developed relating to the detection of microorganisms. Various forms of those methods include the use of spectrometers, chromatographs, and other electronic sensors for detecting the presence of microorganisms. Exemplary U.S. patents include Lewis, et al. U.S. Pat. No. 6,017,440 issued Jan. 25, 2000; Chutjian, et al. U.S. Pat. No. 6,188,067 issued Feb. 13, 2001; Hunter, et al. U.S. Pat. No. 5,811,255 issued Sep. 22, 1998; Overton, et al. U.S. Pat. No. 5,611,846 issued Mar. 18, 1997; and Yu U.S. Pat. No. 5,583,281 issued Dec. 10, 1996.
While such systems have been highly successful in the promotion of wound closure, healing many wounds previously thought untreatable, some difficulty remains. Because the very nature of such systems require an atmospherically sealed wound site, it is difficult to detect the presence or concentration of contaminant microorganisms such as bacteria that may be present in the wound site, without removing the wound dressing. It has heretofore been necessary to disturb the wound site, and thereby interrupt the therapy, in order to test for the presence or concentration of bacterial infection. Furthermore, any disturbance to the wound site may increase the possibility of infection to the wound site. Additionally, removal of the wound dressing may cause pain or discomfort to the patient.
Some progress has been made to circumvent these problems with the invention described in United States Patent Application Publication US2002/0143286, incorporated herein by reference. That application describes the use of sensing devices that optically sense the presence of a bacterial agent or other form of infection in the wound fluid. Other methods to more specifically identify and quantify the infectious agent are desirable.
Accordingly, a primary object of the present invention is to provide a vacuum assisted wound closure device that utilizes a means for detecting the presence of an infection present at a wound site during utilization of an airtight dressing without disturbing the dressing at the wound site.
A further object of the present invention is to provide a means for identifying the nature or specific type of infection present at a wound site during the utilization of an airtight dressing without disturbing the dressing at the wound site.
It is yet a further object of the present invention to provide a means for detecting the concentration of an infecting agent present at a wound site during utilization of an airtight dressing without disturbing the dressing at the wound site.